1. Field Of Invention
This invention relates generally to bedding mattresses, and specifically to mattresses having an improved edge support.
2. Description Of Prior Art
Typically, a mattress comprises a spring core or so-called spring assembly covered on the top and bottom sides by a fabric or cushioning pad and encased within an upholstery covering. The spring core generally comprises rows of coil springs laced together in the top and bottom planes of the springs and surrounded by top and bottom border wires. In addition, a mattress may have edge support springs mounted between the border wires to provide additional stiffness or support around the outer edge of the mattress. The present invention is directed to an improved mattress having resilient support in the form of edge support springs around the outer edge of the mattress.
For many years, the most popular technique for securing border wires to spring cores has been to utilize helical lacing wires around the border wires and the points of contact of the border wires with the coil springs. To this border wire equipped spring core, vertical edge support springs extending between the border wires or rods were often added by utilizing the helical lacing wires to secure the ends of the edge support springs to the border rods or by utilizing hog rings to make this connection. But the application of border wires and edge support springs to the spring core by means of helical lacing wires is a labor intensive and relatively expensive operation. Furthermore, helical lacing wire securement of the border rods to the spring core is relatively "loose" so that movement between the border wires and the coil springs within the lacing wire can result in undesirable "noise". In order to reduce the cost of manufacture of the mattress and eliminate the noise problem, the invention of this application utilizes sheet metal clips for securing the border rods to the springs. Substituting sheet metal clips for helical lacing wires reduces the amount of material used in the mattress spring core which results in lower overall material costs. And, substituting sheet metal clips for helical lacing wires results in assembly time savings thereby reducing total overall manufacturing costs and increasing total output and productivity. This assembly technique also reduces or eliminates the noise problem.
The nature of mattress manufacture is that mattress spring cores, or so-called spring assemblies, are generally manufactured in one manufacturing facility and then shipped to a second, and generally much cleaner, manufacturing facility where the cores are covered and upholstered. In the course of upholstering the spring core of the mattress at the second facility, accessories such as border or edge support springs may be added to the spring core so as to differentiate the core from other mattresses manufactured at the same facility. Mattress upholsterers customarily do not have the equipment for feeding and closing sheet metal clips; consequently, these manufacturers, if they wish to add edge support springs to selective units, must use alternative means for connecting the edge support springs to the mattress border wires. According to the practice of this invention, some other means, such as crimpable wire channels formed in opposite ends of the edge support springs are used to connect edge support springs to the border wires.